Officially, this narrow-tracked, canopy-roofed, electric city car is an L7 category heavy quadricycle, which means that it can weigh up to 400kg, and offer up to 15 kilowatts of power. Its rear-mounted 49bhp motor can whirr it to 62mph in less than 13 seconds, and onto 75mph.

The RAK-e is the electric commuter car made exciting, and for the price of an Agila

So modest is its energy consumption that it requires no more than a year’s worth of output from five square metres of solar panels harvesting energy beneath far-from-totally sunny German skies to propel it 6200 miles. In other words, it’s ultra-economical, costing under a pound to travel the 62 miles that also happens to be its nominal range, which is 10 percent of the cost of running a small hatchback.

Inside, the cockpit is fully enclosed, but like the Renault Twizy there’s no air conditioning, in-cabin cooling achieved by raising the canopy slightly, while seat heaters provide warmth. Instrumentation consists of a single screen providing a speedo, eco gauge and battery range indicator, supplemented by a smartphone that provides navigation and the means to control some functions remotely while the car is charging, such as the seat heaters.

This car really is excitingly different. Besides the drama – and convenience – of that panoramic screen there’s the novelty of the RAK-e’s narrowness, a go-kart-style pedal pairing so that you left-foot brake, a dinky little squared off-wheel, a fixed seat and adjustable pedals. And if you’re carrying one, a passenger that sits in very close but not in uncomfortable proximity.

To go, you merely toggle the prototype rocker switch gear selector hidden close to your right shin, press the accelerator and grind off. Grind? Yes, because this is a prototype, and makes appropriately experimental noises. It also goes quite slowly and steers rather lazily given its low weight, but neither of these characteristics is remotely representative of how the real thing would drive.

But what this concept does hint at, even when driving it in a very large room, is just how much fun it would be to thread through traffic, or to speed along tight, country lanes. Which is why GM has allowed it a higher top speed than most baby commuter cars, its 75mph maximum partly the product of the compact, low drag frontal area afforded by its motorbike seating.

Why wouldn’t you want to buy one, not only as a second or third commuter car, but as a weekend entertainer besides? Insiders say the car is two-and-a-bit years away from the green light. Let’s hope GM dares to illuminate it.